1. Field
The following description relates to a hierarchical cell communication system including a femto base station and a macro base station, and more particularly, to a system where a femto base station recognizes a macro terminal or recognizes a channel between the femto base station and the macro terminal in a hierarchical cell communication system.
2. Description of the Related Art
Recently, studies have been directed towards a hierarchical cell communication system including a femtocell, a macrocell, and one or more mobile terminals. In the hierarchical cell communication system, interference from the femtocell to the macrocell can decrease the efficiency of the overall system. For example, a femtocell may interfere with a signal transmitted from the macrocell to a mobile terminal or macro terminal.
Various methods have been proposed to prevent inter-cell interference, such as coordinated beamforming and the like. However, these methods demand exchanging/sharing of channel information between cells in real-time. The exchanging/sharing of the channel information between cells in real time in the hierarchical cell communication system including the femtocell may be difficult. The femtocell is not directly connected with the macrocell, the femtocell is connected with the macrocell via a network, and thus, information transmitted/received between the femtocell and the macrocell incurs a delay.